I've made one using the same principle as Electron's antenna. In the one pictured I have a 1/8λ in a soup can. Using a 117F at 20W I had 64 RSSI. Before the soup can I had a monster can with ~45 RSSI. Now if we're using an urban set up and don't want a x-wing hanging out we just use a coffee tin which usually allows for 1/4λ and hits mid 80s consistently. The soup can and monster can were both out done simply by using the radio as the refractor.
Electron's
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